122 Animal Life 
and wonderful the sights they saw, for on every branch and from every cell of 
the seaweed-like objects, small; beautifully coloured heads surrounded by gracefully 
waving arms were pushed forth. The tiny arms were seen to catch minute living 
things that swam about in the water, and to convey them to an equally minute 
but hungry mouth which eagerly swallowed them. Having proved their theory 
that the seaweed-like objects were not seaweeds at all but active animal colonies, 
these grave professors divided them up into two classes: those colonies which 
were composed of individuals. without very complicated internal organs, thei external 
anatomy, roughly speaking, consisting of the graceful tentacles and hungry mouth, and 
their internal anatomy chiefly of a capacious stomach, were called Hydrozoa; while the 
colonies consisting of individuals with a more elaborate digestive apparatus were 
christened Bryozoa or Moss Animals, from the moss-like appearance of their surface to 
the naked eye when all the little heads are seen protruding from their cells. 
The hydrozoa have since proved to be most interesting creatures, undergoing all 
sorts of quaint and remarkable changes; indeed the whole life history of these remarkable 
little animals 
is most won- 
derful and 
romantic, — for 
now we know 
that many of 
them by no 
means spend 
the whole of 
their lives as 
respectable 
and indus- 
trious mem- 
bers of the 
colony, all 
working for 
DINNER TIME. A SIESTA. 
the common 
Part of a living colony of Moss Animals on The Moss Animals take a rest while the a 1. but = 
the look out for a meal. “Bird’s-heads’’ mount guard. good, u im 
their youthful 
days go gadding about in such guise that their own relations would hardly recognise them. 
In the spring time of the year many of the cup-like cells, or Gonophores, on the 
stems of a colony of hydrozoa are closed at the top, and begin to grow larger until 
they become quite prominent objects and are seen to contain bunches of vimy round 
or oval bodies. Then the lids of the cups open and out come little surprise babies 
that have been formed within. Certainly their appearance must be as astonishing to 
the rest of the colony as the behaviour of young ducklings on catching sight of a 
pond is to a too confiding mother hen, for these veritable surprise babies have not 
the remotest resemblance to the individual hydroid; im fact, unless you actually saw 
them come out from the doors of the colony, you would never credit them with their 
real parentage, for instead of coming into the world as little polypes, with hungry 
mouths and graceful waving tentacles, they make their first appearance as miniature 
Jelly-fish. 
After these young jelly-fish, or Medusz, as scientific men call them, haye enjoyed 
themselves for a time, swimming about and seeing the world, the more sober-minded 
amongst them renounce thei roving ways and choosing a likely spot settle down in 
life as staid and respectable founders of a new colony, which in time becomes identical 
